• 대한소아치과학회지
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• 제33권2호
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• pp.233-243
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• 2006

와동 형성시 C-factor와 충전방법이 복합레진 수복물에서의 수축 응력에 미치는 영향을 평가하고자 발거된 소구치를 대상으로 C-factor가 3.6과 1.0인 와동을 각각 형성한 후 hybrid형 복합레진인 $Z-250^{TM}$(3M ESPE U.S.A.)과 flowable형 복합레진인 $Filtek\;flow^{TM}$(3M ESPE U.S.A.)를 사용하여 layering을 시행하고 광중합하면서 strain gauge법을 이용하여 치질에서의 수축 응력을 측정하였다. 시편을 절단하여 레진과 상아질 사이 계면의 접착상태를 주사전자현미경으로 관찰한 결과 다음과 같은 결과를 얻었다. 1. C-factor에 따른 수축 응력을 측정한 결과 C-factor가 3.7인 제 1군과 제 2군 그리고 제 5군이 900초 후 각각 0.11, 0.07, 0.07 MPa로 C-factor가 1.0인 제 3군과 제 4군의 0.05와 0.04 MPa에 비해 크게 나타났다(P<0.05). 1,800초 후에는 제 1군, 제 5군, 제 2군, 제 3군, 제 4순으로 크게 나타났으나 제 2군과 제 3군 그리고 제 3군과 제 4군 사이에는 유의성이 없었다. 2. 재료에 따른 수축 응력의 차이는 C-factor가 3.7인 와동의 경우 hybrid형 레진인 Filtek $Z-250^{TM}$이 flowable 레진인 $Filtek\;flow^{TM}$에 비해 수축 응력이 크게 나타났으나(P<0.05), C-factor가 1.0인 와동의 경우 재료의 차이에 따른 수축응력의 유의한 차이가 없었다. 3. Layering에 따른 수축 응력은 Filtek $Z-250^{TM}$을 layering 없이 bulk 충전한 제 1군에 비해 flowable 레진을 layering한 제 5군이 전 측정 시간대에 걸쳐 수축 응력이 유의하게 낮게 나타났다(P<0.05). 4. C-factor가 3.7인 제 1군과 제 2군 제 5군은 900초까지 수축 응력이 증가하다 이후 점차 감소하는 경향을 보였다. 5. C-factor가 1.0인 와동의 경우 충전용 레진 종류에 관계없이 레진과 와동벽 사이에 긴밀한 접착 상태를 보였으나 C-factor가 3.7인 와동의 경우 부분적으로 틈이 관찰되었다. 전반적으로 와동저에 비해 와동벽에서 틈이 더 많이 관찰되었다. 이상의 결과를 종합하여 보면 복합레진 수복시 수축응력에 따른 합병증을 예방하기 위해 C-factor를 크지 않게 와동을 설계, 형성하여야 하며 C-factor가 클 경우 flowable 레진을 이장하는 등 재료적인 면에서의 선택과 적용법이 중요할 것으로 사료된다.

• 동굴
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• 제68호
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• pp.23-73
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• 2005

Purpose of study; The purpose of this study is specifically classified as two parts. The one is to attempt the chronological annals of Quaternary topographic surface through the study over the formation process of alluvial surfaces in our country, setting forth the alluvial surfaces lower-parts of Han River area, as the basic deposit, and comparing it to the marginal landform surfaces. The other is to attempt the classification of micro morphology based on the and condition premising the land use as a link for the regional development in the lower-parts of Han river area. Reasons why selected the Lower-parts of Han river area as study objects: 1. The change of river course in this area is very serve both in vertical and horizontal sides. With a situation it is very easy to know about the old geography related to the formation process of topography. 2. The component materials of gravel, sand, silt and clay are deposited in this area. Making it the available data, it is possible to consider about not oかy the formation process of topography but alsoon the development history to some extent. 3. The earthen vessel, a fossil shell fish, bone, cnarcoal and sea-weed are included in the alluvial deposition in this area. These can be also valuable data related to the chronological annals. 4. The bottom set conglometate beds is also included in the alluvial deposits. This can be also valuable data related to the research of geomorphological development. 5. Around of this area the medium landform surface, lower landform surface, pediment and basin, are existed, and these enable the comparison between the erosion surfaces and the alluvial surfaces. Approach : 1. Referring to the change of river beds, I have calculated the vertical and horizontal differences comparing the topographic map published in 1916 with that published in 1966 and through the field work 2. In classifying the landform, I have applied the method of micro morphological classification in accordance with the synthetic index based upon the land conditions, and furthermore used the classification method comparing the topographic map published in 1916 and in that of 1966. 3. I have accorded this classification with the classification by mapping through appliying the method of classification in the development history for the field work making the component materials as the available data. 4. I have used the component materials, which were picked up form the outcrop of 10 places and bored at 5 places, as the available data. 5. I have referred to Hydrological survey data of the ministry of Construction (since 1916) on the overflow of Han-river, and used geologic map of Seoul metropolitan area. Survey Data, and general map published in 1916 by the Japanese Army Survbey Dept., and map published in 1966 by the Construction Research Laboratory and ROK Army Survey Dept., respectively. Conclusion: 1. Classification of Morphology: I have added the historical consideration for development, making the component materials and fossil as the data, to the typical consideration in accordance with the map of summit level, reliefe and slope distribution. In connection with the erosion surface, I have divided into three classification such as high, medium and low-,level landform surfaces which were classified as high and low level landform surfaces in past. furthermore I have divided the low level landform surface two parts, namely upper-parts(200-300m) and bellow-parts(${\pm}100m$). Accordingly, we can recognize the three-parts of erosion surface including the medium level landform surface (500-600m) in this area. (see table 22). In condition with the alluvial surfaces I have classified as two landform surfaces (old and new) which was regarded as one face in past. Meamwhile, under the premise of land use, the synthetic, micro morphological classification based upon the land condition is as per the draw No. 19-1. This is the quite new method of classification which was at first attempted in this country. 2. I have learned that the change of river was most severe at seeing the river meandering rate from Dangjung-ni to Nanjido. As you seee the table and the vertical and horizontal change of river beds is justly proportionable to the river meandering rate. 3. It can be learned at seeing the analysis of component materials of alluvial deposits that the component from each other by areas, however, in the deposits relationship upper stream, and between upper parts and below parts I couldn't always find out the regular ones. 4. Having earthern vessel, shell bone, fossil charcoal and and seaweeds includen in the component materials such as gravel, clay, sand and silt in Dukso and Songpa deposits area. I have become to attempt the compilation of chronicle as yon see in the table 22. 5. In according to hearing of basemen excavation, the bottom set conglomerate beds of Dukso beds of Dukso-beds is 7m and Songpa-beds is 10m. In according to information of dredger it is approx. 20m in the down stream. 6. Making these two beds as the standard beds, I have compared it to other beds. 7 The coarse sand beds which is covering the clay-beds of Dukso-beds and Nanjidobeds is shown the existence of so-called erosion period which formed the gap among the alluvial deposits of stratum. The former has been proved by the sorting, bedding and roundness which was supplied by the main stream and later by the branch stream, respectively. 8. If the clay-beds of Dukeo-bed and Songpa-bed is called as being transgressive overlap, by the Eustatic movement after glacial age, the bottom set conglomerate beds shall be called as being regressive overlap at the holocene. This has the closest relationship with the basin formation movement of Seoul besides the Eustatic movement. 9. The silt-beds which is the main component of deposits of flood plain, is regarded as being deposited at the Holocene in the comb ceramic and plain pottery ages. This has the closest relationship with the change of river course and river beds.